A normal curve isa. positively skewed b. negatively skewed c. symmetric d. bimodal

To determine the correct description of a normal curve, we need to analyze the characteristics of each option presented:

1. Positively Skewed: This describes a distribution where the tail on the right side is longer or fatter than the left side. It indicates that most values are clustered to the left.

2. Negatively Skewed: This is the opposite of positively skewed; it describes a distribution where the left tail is longer or fatter than the right side, meaning most values are clustered to the right.

3. Symmetric: A symmetric distribution is one where the left and right sides are mirror images of each other. This is the defining characteristic of a normal curve.

4. Bimodal: A bimodal distribution has two different modes or peaks, which is contrary to the single-peaked structure of a normal curve.

Conclusion:

The correct answer is c. symmetric, since a normal curve is defined as a symmetric distribution centered around the mean.